RT Journal Article SR Electronic T1 EP439 Predictive value of preoperative serum squamous cell carcinoma antigen (SCC-Ag) level on tumor recurrence in cervical squamous cell carcinoma patients treated with radical surgery: a single-institution study JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A285 OP A285 DO 10.1136/ijgc-2019-ESGO.498 VO 29 IS Suppl 4 A1 Q Guo A1 J Zhu A1 X Ju A1 X Wu YR 2019 UL http://ijgc.bmj.com/content/29/Suppl_4/A285.1.abstract AB Introduction/Background We seek to find the significance of serum squamous cell carcinoma antigen (SCC-Ag) and the optimal cut-off value for predicting tumor recurrence and survival in cervical squamous cell carcinoma receiving radical surgery.Methodology A total of 3471 patients with stages IB1 to IIA2 cervical squamous cell carcinoma who underwent radical surgery were enrolled in this study. The cut-off value of serum SCC-Ag for tumor recurrence was calculated using the receiver operating characteristic (ROC) curve. The progression-free survival (PFS) and overall survival (OS) were assessed to estimate the significance of SCC-Ag.Results The optimal cut-off value of serum SCC-Ag level for predicting tumor recurrence was calculated and set at 2.75ng/mL. Compared with 1.5 ng/mL used in clinical practice, serum SCC-Ag level >2.75 ng/mL was closely related to extrapelvic metastatic disease when patients relapse (P=0.035). Multivariate analysis showed that serum SCC-Ag level >1.5 ng/mL and serum SCC-Ag level >2.75 ng/mL were neither independent risk factors for PFS nor OS in all the patients. But in 964 patients with one or more high-risk factors (parametrial invasion, vaginal margin invasion and lymph node metastasis), instead of serum SCC-Ag level >1.5 ng/mL, serum SCC-Ag level >2.75 ng/mL could be used as an independent factor affecting PFS (P=0.018, HR=1.538).Conclusion Preoperative serum SCC-Ag level >2.75 ng/mL is closely related to extrapelvic recurrence, and is an independent factor for tumor recurrence and survival in cervical squamous cell carcinoma patients with high-risk factors.Disclosure Nothing to disclose.